4,725 research outputs found
Executive Incentive Compensation and Economic Prosperity
This paper analyzes the existence of a potential link between the prevalence of long term incentive compensation schemes and the economic prosperity of a country. This issue is previously not addressed in the literature. In a panel regression with fixed effects a strongly significant, positive effect is found between growth of GDP/capita in real terms and this prevalence, while controlling for general investment and institutional variables. However, when the 22 countries of the study are divided into European and non-European, the growth effect found for the entire material accrues only to the non-European countries. It is concluded that long term incentive contracts seem to have no effect in the European countries due to labor market and cultural reasons
Syncope diagnosis at referral to a tertiary syncope unit: an in-depth analysis of the fast II
OBJECTIVE: A substantial number of patients with a transient loss of consciousness (T-LOC) are referred to a tertiary syncope unit without a diagnosis. This study investigates the final diagnoses reached in patients who, on referral, were undiagnosed or inaccurately diagnosed in secondary care. METHODS: This study is an in-depth analysis of the recently published Fainting Assessment Study II, a prospective cohort study in a tertiary syncope unit. The diagnosis at the tertiary syncope unit was established after history taking (phase 1), following autonomic function tests (phase 2), and confirming after critical follow-up of 1.5-2 years, with the adjudicated diagnosis (phase 3) by a multidisciplinary committee. Diagnoses suggested by the referring physician were considered the phase 0 diagnosis. We determined the accuracy of the phase 0 diagnosis by comparing this with the phase 3 diagnosis. RESULTS: 51% (134/264) of patients had no diagnosis upon referral (phase 0), the remaining 49% (130/264) carried a diagnosis, but 80% (104/130) considered their condition unexplained. Of the patients undiagnosed at referral, three major causes of T-LOC were revealed: reflex syncope (69%), initial orthostatic hypotension (20%) and psychogenic pseudosyncope (13%) (sum > 100% due to cases with multiple causes). Referral diagnoses were either inaccurate or incomplete in 65% of the patients and were mainly altered at tertiary care assessment to reflex syncope, initial orthostatic hypotension or psychogenic pseudosyncope. A diagnosis of cardiac syncope at referral proved wrong in 17/18 patients. CONCLUSIONS: Syncope patients diagnosed or undiagnosed in primary and secondary care and referred to a syncope unit mostly suffer from reflex syncope, initial orthostatic hypotension or psychogenic pseudosyncope. These causes of T-LOC do not necessarily require ancillary tests, but can be diagnosed by careful history-taking. Besides access to a network of specialized syncope units, simple interventions, such as guideline-based structured evaluation, proper risk-stratification and critical follow-up may reduce diagnostic delay and improve diagnostic accuracy for syncope
van der Kruit to Spitzer: A New Look at the FIR-Radio Correlation
We present an initial look at the far infrared-radio correlation within the
star-forming disks of four nearby, nearly face-on galaxies (NGC~2403, NGC~3031,
NGC~5194, and NGC~6946). Using {\it Spitzer} MIPS imaging and WSRT radio
continuum data, we are able to probe variations in the logarithmic
70~m/22~cm () flux density ratios across each disk at sub-kpc
scales. We find general trends of decreasing with declining surface
brightness and with increasing radius. We also find that the dispersion in
within galaxies is comparable to what is measured {\it globally} among
galaxies at around 0.2 dex. We have also performed preliminary phenomenological
modeling of cosmic ray electron (CR) diffusion using an image-smearing
technique, and find that smoothing the infrared maps improves their correlation
with the radio maps. The best fit smoothing kernels for the two less active
star-forming galaxies (NGC~2403 and NGC~3031) have much larger scale-lengths
than that of the more active star-forming galaxies (NGC~5194 and NGC~6946).
This difference may be due to the relative deficit of recent CR
injection into the interstellar medium (ISM) for the galaxies having largely
quiescent disks.Comment: 6 pages, 3 figures, To appear in the proceedings of the "Island
Universes: Structure and Evolution of Disk Galaxies" conference held in
Terschelling, Netherlands, July 2005, ed. R. de Jong (Springer: Dordrecht
The galaxy environment in GAMA G3C groups using the Kilo Degree Survey Data Release 3
We aim to investigate the galaxy environment in GAMA Galaxy Groups Catalogue
(G3C) using a volume-limited galaxy sample from the Kilo Degree Survey Data
Release 3. The k-Nearest Neighbour technique is adapted to take into account
the probability density functions (PDFs) of photometric redshifts in our
calculations. This algorithm was tested on simulated KiDS tiles, showing its
capability of recovering the relation between galaxy colour, luminosity and
local environment. The characterization of the galaxy environment in G3C groups
shows systematically steeper density contrasts for more massive groups. The red
galaxy fraction gradients in these groups is evident for most of group mass
bins. The density contrast of red galaxies is systematically higher at group
centers when compared to blue galaxy ones. In addition, distinct group center
definitions are used to show that our results are insensitive to center
definitions. These results confirm the galaxy evolution scenario which
environmental mechanisms are responsible for a slow quenching process as
galaxies fall into groups and clusters, resulting in a smooth observed colour
gradients in galaxy systems.Comment: 14 pages, Accepted to MNRA
Optimization of supply diversity for the self-assembly of simple objects in two and three dimensions
The field of algorithmic self-assembly is concerned with the design and
analysis of self-assembly systems from a computational perspective, that is,
from the perspective of mathematical problems whose study may give insight into
the natural processes through which elementary objects self-assemble into more
complex ones. One of the main problems of algorithmic self-assembly is the
minimum tile set problem (MTSP), which asks for a collection of types of
elementary objects (called tiles) to be found for the self-assembly of an
object having a pre-established shape. Such a collection is to be as concise as
possible, thus minimizing supply diversity, while satisfying a set of stringent
constraints having to do with the termination and other properties of the
self-assembly process from its tile types. We present a study of what we think
is the first practical approach to MTSP. Our study starts with the introduction
of an evolutionary heuristic to tackle MTSP and includes results from extensive
experimentation with the heuristic on the self-assembly of simple objects in
two and three dimensions. The heuristic we introduce combines classic elements
from the field of evolutionary computation with a problem-specific variant of
Pareto dominance into a multi-objective approach to MTSP.Comment: Minor typos correcte
Current induced switching of magnetic domains to a perpendicular configuration
In a ferromagnet--normal-metal--ferromagnet trilayer, a current flowing
perpendicularly to the layers creates a torque on the magnetic moments of the
ferromagnets. When one of the contacts is superconducting, the torque not only
favors parallel or antiparallel alignment of the magnetic moments, as is the
case for two normal contacts, but can also favor a configuration where the two
moments are perpendicular. In addition, whereas the conductance for parallel
and antiparallel magnetic moments is the same, signalling the absence of giant
magnetoresistance in the usual sense, the conductance is greater in the
perpendicular configuration. Thus, a negative magnetoconductance is predicted,
in contrast with the usual giant magnetoresistance.Comment: 4 pages, 3 figures, major rewriting of the technical par
Andreev Reflection in Ferromagnet/Superconductor/Ferromagnet Double Junction Systems
We present a theory of Andreev reflection in a
ferromagnet/superconductor/ferromagnet double junction system. The spin
polarized quasiparticles penetrate to the superconductor in the range of
penetration depth from the interface by the Andreev reflection. When the
thickness of the superconductor is comparable to or smaller than the
penetration depth, the spin polarized quasiparticles pass through the
superconductor and therefore the electric current depends on the relative
orientation of magnetizations of the ferromagnets. The dependences of the
magnetoresistance on the thickness of the superconductor, temperature, the
exchange field of the ferromagnets and the height of the interfacial barriers
are analyzed. Our theory explains recent experimental results well.Comment: 8 pages, 9 figures, submitted to Phys. Rev.
Multiwavelength star formation indicators: Observations
We present a compilation of multiwavelength data on different star formation
indicators for a sample of nearby star forming galaxies. Here we discuss the
observations, reductions and measurements of ultraviolet images obtained with
STIS, on board the Hubble Space Telescope, ground-based Halpha, and VLA 8.46
GHz radio images. These observations are complemented with infrared fluxes, as
well as large aperture optical radio and ultraviolet data from the literature.
This database will be used in a forthcoming paper to compare star formation
rates at different wavebands. We also present spectral energy distributions
(SEDs) for those galaxies with at least one far-infrared measurements from ISO,
longward of 100 um. These SEDs are divided in two groups, those which are
dominated by the far-infrared emission, and those where the contribution from
the far-infrared and optical emission is comparable. These SEDs are useful
tools to study the properties of high redshift galaxies.Comment: 39 pages, 17 jpeg figures, 1 eps figure, To appear in ApJS May 200
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